Physical Review Materials

Ferroelectric domain architecture and poling of BaTiO3 on Si

Download paper


We investigate the ferroelectric domain architecture and its operando response to an external electric field in BaTiO3-based electro-optic heterostructures integrated on silicon. By noninvasive optical second-harmonic generation, we identify the preexistence of in-plane (a-) domains dispersed within a predominantly out-of-plane-(c-) oriented matrix. Monitoring the poling behavior of the respective domain populations, we show that the spontaneous polarization of these a-domains lack a predominant orientation in the pristine state, yet can be selectively aligned with an in-plane electric field, leaving the c-domain population intact. Hence, domain reorientation of a ferroelastic c-to-a type was directly excluded. Such independent electrical control of ferroelectric a-domains in a c-oriented BaTiO3 film on silicon is a valuable platform for engineering multidirectional electro-optic functionality in integrated photonic devices.